Origin of strong magnetic anisotropy in L10-FeNi probed by angular-dependent magnetic circular dichroism

Abstract

We investigated the origin of strong magnetic anisotropy energy (MAE) in L10-type ordered FeNi phase by angular-dependent magnetic circular dichroism. Our findings showed that the orbital magnetic moment of Fe has a significant angular dependence that exhibits a maximum value at the [001] direction corresponding perpendicular to the plane. The calculated uniaxial anisotropy energy when considering spin–orbit (SO) interaction shows quantitatively good agreement with the volume MAE. We concluded that the orbital anisotropy in 3d Fe electrons results in the strong MAE in L10-FeNi and ascribe this to the spin–orbit interaction via structural ordering.